CN111313013A - Preparation method and application of lithium-tin alloy powder for lithium ion battery cathode - Google Patents
Preparation method and application of lithium-tin alloy powder for lithium ion battery cathode Download PDFInfo
- Publication number
- CN111313013A CN111313013A CN202010135160.2A CN202010135160A CN111313013A CN 111313013 A CN111313013 A CN 111313013A CN 202010135160 A CN202010135160 A CN 202010135160A CN 111313013 A CN111313013 A CN 111313013A
- Authority
- CN
- China
- Prior art keywords
- lithium
- tin alloy
- alloy powder
- ion battery
- tin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/40—Alloys based on alkali metals
- H01M4/405—Alloys based on lithium
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention provides a preparation method and application of lithium tin alloy powder for a lithium ion battery cathode, which is characterized by comprising the following steps: flatly attaching a tin-based foil and a lithium strip together to obtain a stacked metal sheet; pressing the stacked metal sheets through pressure equipment in a dry oxygen-free environment to enable the tin-based foil to be completely embedded into the lithium belt, so as to obtain lithium-tin alloy metal sheets; and step three, grinding the lithium-tin alloy metal sheet into lithium-tin alloy powder by grinding equipment in a dry oxygen-free environment. The particle size of the prepared lithium-tin alloy powder is 10-100 mu m, and the lithium-tin alloy powder is added into a negative electrode for lithium supplement, so that the first-turn coulomb efficiency and the cycling stability of the battery can be improved. The lithium tin alloy powder for the lithium ion battery cathode is simple to prepare and operate, has mature technology, and can be used for lithium supplement of various cathode materials, so that the lithium tin alloy powder has a wide development prospect in a lithium supplement process of the lithium ion battery.
Description
Technical Field
The invention belongs to the field of lithium ion secondary batteries, and particularly relates to a preparation method and application of lithium tin alloy powder for a lithium ion battery cathode.
Background
In the first charging process of the lithium ion battery, the organic electrolyte is reduced and decomposed on the surface of a negative electrode material to form a Solid Electrolyte Interface (SEI), and a large amount of lithium from a positive electrode is permanently consumed, so that the first cycle coulombic efficiency (ICE) is low, and the capacity and the energy density of the lithium ion battery are reduced. For common cathode materials, graphite has 5% -10% of first irreversible lithium loss, and for high-capacity cathode materials, the influence is more obvious, and the irreversible capacity loss of silicon can reach 15% -35%, so that the lost lithium is supplemented to a lithium ion battery, lithium supplement can be performed by taking a lithium-rich metal oxide as a positive electrode, but the effect of lithium supplement of the positive electrode is not ideal, wherein the energy density of the battery can be reduced by residual inactive compounds at the positive electrode; meanwhile, potential safety hazards and the like can exist due to the large lithium content.
The lithium supplement process of the negative electrode is a more common pre-lithiation method, wherein the lithium supplement of lithium foil and the lithium supplement of lithium powder are the pre-lithiation processes which are mainly developed at present. Lithium foil lithium supplement is a technique utilizing a self-discharge mechanism, and due to the existence of a potential difference, when a negative electrode material is in contact with a metal lithium foil, electrons spontaneously move to the negative electrode, accompanied by Li+The intercalation in the negative electrode thus achieves the effect of prelithiation. However, the degree of pre-lithiation is not easy to control precisely, insufficient lithiation cannot improve ICE sufficiently, and excessive lithium supplementation may form a metal-plated lithium layer on the surface of the negative electrode, which limits the application of the lithium-plated lithium ion secondary battery to a certain extent.
Lithium is mended to lithium powder and then adds lithium powder in the thick liquids of slurrying in-process addition, perhaps directly adds lithium powder to the surface of negative pole piece to reach the effect of mending lithium, lithium is mended to lithium powder can be through the addition control of lithium powder lithiation degree in advance, and this is very important to control experiment precision, both can not cause the waste of lithium and can not reach anticipated effect because of lithiation degree inadequately in advance.
The lithium powder is produced by a complicated process, and the particle size is generally between 10 μm and 100 μm as a commercial standard, so that it is neither difficult to use because of too large particle size nor agglomerated because of too small particle size. Because of the particularity of lithium powder, if long-distance transportation or storage is required, the obtained lithium powder needs to be subjected to inert treatment, so that the lithium powder is actually the inert lithium powder, and the cost is greatly increased due to the inert treatment. The principle of the preparation method of the inert lithium powder of BYD is as follows: firstly, adding metallic lithium into a first solvent under an inert atmosphere, wherein the first solvent does not react with the metallic lithium, heating until the metallic lithium is molten, stirring to disperse the molten metallic lithium, cooling, cleaning and drying to obtain lithium powder particles; secondly, adding metal salt into a second solvent under inert atmosphere to obtain a solution, wherein the second solvent does not react with metal lithium, adding the obtained lithium powder particles into the second solvent, carrying out in-situ reduction reaction on the lithium powder particles and the metal salt, and cleaning and drying a reaction product to obtain passivated lithium powder. Wherein the first solvent is one or two of liquid paraffin and mineral oil; the second solvent is one or more of copper, nickel, iron, zinc, lead, silver, cadmium and cobalt salt (the solvent is carbonic ester). The japanese TDK patent also achieves similar effects: firstly preparing stabilized lithium powder containing an inorganic protective layer, wherein the inorganic metal contains iron and strontium with the mass ratio of 0.21-2.51, and finally introducing carbon dioxide and trace metal in a molten state to perform a surface protective layer reaction to obtain inert lithium powder. The method for passivating lithium powder in the Tianqi lithium industry comprises the steps of adding metal lithium into 4, 4' -dimethyl biphenyl, sealing and heating to 200-250 ℃, dispersing the metal lithium into small liquid drops, and then taking out the small liquid drops and cooling to obtain inert lithium powder. Other inert lithium powders have similar processes, and the complexity of the process of "inerting" can be seen from these steps, which increases the cost and makes industrialization difficult, so that if a simple preparation process can be used to obtain low-cost lithium powder, it is significant for the development of prelithiation.
Disclosure of Invention
The present invention is made to solve the above problems, and an object of the present invention is to provide a method for preparing a lithium-tin alloy powder for a negative electrode of a lithium ion battery and an application thereof, wherein the lithium powder which can be used for lithium supplement of a negative electrode material is prepared by using an industrially available tin foil and a lithium ribbon through mechanical stress, and is used for lithium supplement of a negative electrode material of a lithium ion battery to improve the first coulombic efficiency and the cycle stability thereof.
The invention provides a preparation method of lithium tin alloy powder for a lithium ion battery cathode, which is characterized by comprising the following steps of:
flatly attaching a tin-based foil and a lithium strip together to obtain a stacked metal sheet;
pressing the stacked metal sheets through pressure equipment in a dry oxygen-free environment to enable the tin-based foil to be completely embedded into the lithium belt, so as to obtain lithium-tin alloy metal sheets;
and step three, grinding the lithium-tin alloy metal sheet into lithium-tin alloy powder by grinding equipment in a dry oxygen-free environment.
The method for preparing the lithium-tin alloy powder for the negative electrode of the lithium ion battery provided by the invention can also have the following characteristics: wherein, the grain diameter of the lithium-tin alloy powder in the third step is 10-100 μm.
The method for preparing the lithium-tin alloy powder for the negative electrode of the lithium ion battery provided by the invention can also have the following characteristics: wherein, the tin-based foil is a tin-based alloy foil, and the tin-based alloy refers to an alloy formed by tin and one or more of copper, silver, antimony, cobalt, zinc, antimony, bismuth and indium.
The method for preparing the lithium-tin alloy powder for the negative electrode of the lithium ion battery provided by the invention can also have the following characteristics: wherein the tin-based foil is pure tin foil.
The method for preparing the lithium-tin alloy powder for the negative electrode of the lithium ion battery provided by the invention can also have the following characteristics: wherein the pressure equipment is one of a hot press, a tablet press and a cold press,
the pressing process in the second step is as follows: and pressing the stacked metal sheets for 3-6 h under the pressure of 5-30 MPa by using pressure equipment to obtain the lithium-tin alloy metal sheets.
The method for preparing the lithium-tin alloy powder for the negative electrode of the lithium ion battery provided by the invention can also have the following characteristics: wherein, the thickness of the tin-based foil in the step one is 15-30 μm, and the thickness of the lithium belt is 40-100 μm.
The method for preparing the lithium-tin alloy powder for the negative electrode of the lithium ion battery provided by the invention can also have the following characteristics: wherein the pressure equipment is a roller press,
the pressing process in the second step is as follows: the distance between the two roll shafts of the roller press is set to be smaller than the thickness of the stacked metal sheet, the stacked metal sheet is rolled for 5-10 times through the roller press, and the distance between the two roll shafts is reduced after each rolling.
The invention also provides lithium tin alloy powder for the lithium ion battery cathode, which is characterized in that the lithium tin alloy powder for the lithium ion battery cathode is prepared by the preparation method of the lithium tin alloy powder for the lithium ion battery cathode.
The invention also provides application of the lithium-tin alloy powder for the lithium ion battery cathode in the lithium ion battery cathode, which is characterized in that the lithium-tin alloy powder is added into the lithium ion battery cathode as an active substance.
The invention also provides application of the lithium-tin alloy powder for the lithium ion battery cathode in the lithium ion battery cathode, which is characterized in that the lithium-tin alloy powder is taken as an active substance and is hot-pressed into the lithium ion battery cathode.
Action and Effect of the invention
According to the preparation method and the application of the lithium tin alloy powder for the lithium ion battery cathode, provided by the invention, the lithium tin alloy powder for lithium supplement of the cathode material can be prepared through mechanical stress alloying, the lithium powder can well show the pre-lithiation effect and advantage, the air stability is realized without coating of an inert layer, the particle size is 10-100 mu m, and the commercial standard is met. The structure of the obtained powder can be determined through XRD detection, and the method is favorable for quantification of prelithiation added lithium. Meanwhile, tin can also be used as an active material without reducing the capacity of the anode material, which makes the present invention have great industrial potential.
The lithium-tin alloy powder can be used for lithium supplement of various cathode materials, such as graphite cathode materials, hard carbon cathode materials, silicon-carbon cathode materials and the like, which can be basically added in cathode materials in the prior art. The obtained lithium-tin alloy powder is added into the negative electrode through pulping or hot pressing to obtain a pre-lithiated negative electrode, and the negative electrode is used for assembling a battery, so that the coulomb efficiency of the lithium battery can be improved. In the discharging process of the battery, the shell of the lithium-tin alloy powder is broken, so that more lithium can be released, and the lithium-tin alloy powder can be used as a lithium source for lithium supplement.
Therefore, the preparation method of the lithium tin alloy powder for the lithium ion battery cathode is simple and feasible, the technology is mature, the lithium tin alloy powder can be conveniently used for lithium supplement in a plurality of cathode materials, and the lithium tin alloy powder has a wide development prospect in the lithium supplement process of the lithium ion battery.
Drawings
Fig. 1 is a schematic flow chart of a method for preparing a lithium-tin alloy powder for a negative electrode of a lithium ion battery in an embodiment of the present invention;
FIG. 2 is a view of a tin-based foil and a lithium ribbon bonded together before pressing in an embodiment of the invention, wherein FIG. 2a is a side of the lithium ribbon and FIG. 2b is a side of the tin-based foil;
FIG. 3 illustrates a tin-based foil and a lithium ribbon during pressing in an embodiment of the present invention;
FIG. 4 is a pressed lithium tin alloy metal sheet;
FIG. 5 is a scanning electron micrograph of a lithium tin alloy powder in example 1 of the present invention;
FIG. 6 is a graph showing the results of X-ray diffraction (XRD) measurement of the lithium tin alloy powder in example 1 of the present invention;
fig. 7 is a voltage-capacity charge-discharge curve diagram of the battery in test example 2;
fig. 8 is a charge-discharge curve graph of voltage versus specific capacity of half cell B in test example 3; and
fig. 9 is a charge-discharge curve diagram of a voltage-specific capacity diagram of half cell a in test example 3.
Detailed Description
In order to make the technical means, the creation features, the achievement objects and the effects of the present invention easy to understand, the following will specifically describe the preparation method and the application of the lithium tin alloy powder for the lithium ion battery cathode according to the present invention with reference to the embodiments and the accompanying drawings.
In the examples of the present invention, the materials used were purchased from general commercial sources unless otherwise specified.
The preparation process of the anode material slurry used in the present invention is identical to that of a general anode material slurry. Namely: the lithium-tin alloy powder, the active material, the conductive agent and the binder are weighed according to the proportion, put into a container and stirred uniformly, and then the obtained slurry is uniformly coated on a current collector.
The active material, the conductive agent and the binder in the pulping process are common commercial products, and the pole piece involved in hot pressing is also a common commercial product.
In the embodiment of the invention, the active material is a hard carbon negative electrode material, the conductive agent is SuperP (conductive carbon black), the binder is PVDF (polyvinylidene fluoride), and the pole pieces are a graphite negative electrode material pole piece and a silicon carbon negative electrode material pole piece.
The materials used in the embodiments of the present invention are examples, and in other embodiments, active materials, conductive agents, adhesives, and pole pieces that achieve the same technical effects can be used.
Fig. 1 is a schematic flow chart of a method for preparing a lithium-tin alloy powder for a negative electrode of a lithium ion battery in an embodiment of the present invention; FIG. 2 is a view of a tin-based foil and a lithium ribbon bonded together before pressing in an embodiment of the invention, wherein FIG. 2a is a side of the lithium ribbon and FIG. 2b is a side of the tin-based foil; FIG. 3 illustrates a tin-based foil and a lithium ribbon during pressing in an embodiment of the present invention; fig. 4 is a pressed lithium tin alloy metal sheet.
As shown in fig. 1 to 4, in an embodiment of the present invention, a method for preparing lithium tin alloy powder for a negative electrode of a lithium ion battery includes the following steps:
flatly attaching a tin-based foil and a lithium strip together to obtain a stacked metal sheet;
pressing the stacked metal sheets through pressure equipment in a dry oxygen-free environment to enable the tin-based foil to be completely embedded into the lithium belt, so as to obtain lithium-tin alloy metal sheets;
and step three, grinding the lithium-tin alloy metal sheet into lithium-tin alloy powder in a dry oxygen-free environment.
In the first step, the surface of the tin-based foil is wiped clean by alcohol, the tin-based foil is repeatedly rolled to be flat by a roller press, then the lithium strip is cut into the size same as that of the tin-based foil, the tin-based foil and the lithium strip are flatly attached together in a glove box, the thickness of the tin-based foil is 15-30 microns, and the thickness of the lithium strip is 40-100 microns.
The tin-based foil can be pure tin foil or tin-based alloy foil doped with various elements. The tin-based alloy refers to an alloy composed of tin and one or more of copper, silver, antimony, cobalt, zinc, antimony, bismuth and indium. In the embodiments of the present invention, only the tin-based foils made of pure tin, tin-copper alloy, tin-cobalt alloy, tin-zinc-antimony alloy, and tin-indium alloy are taken as examples for illustration, but the tin-based foils made of other alloys can achieve the same technical effects.
In the second step, the pressure equipment is a tablet press or a roller, and the pressing process in the second step is as follows: and pressing the stacked metal sheets for 5-8 h under the pressure of more than 30MPa by using pressure equipment to obtain the lithium-tin alloy metal sheet with certain brittleness. The dry oxygen-free environment is a glove box.
And in the third step, the lithium-tin alloy metal sheet is ground into lithium-tin alloy powder through grinding equipment, wherein the particle size of the lithium-tin alloy powder is 10-100 microns.
The prepared lithium-tin alloy powder is used for a lithium ion battery cathode, and the assembly method of the lithium ion battery comprises the following steps: and putting a commercial 500-micron lithium sheet into the negative electrode shell, then putting a 16-mm-diameter polypropylene (PP) diaphragm, adding 30-L of commercial electrolyte (1M LiPF6+ EC: DEC ═ 1:1) and wetting the diaphragm, then putting the prepared negative electrode sheet into the center of the diaphragm, enabling the side containing the active material to face the lithium sheet, then putting a gasket, an elastic sheet and a positive electrode shell in sequence, and finally packaging the battery.
< example 1>
Pure tin foil with the thickness of 15 mu m and a lithium belt with the thickness of 40 mu m are selected, pressed for 5 hours by a tablet press in a glove box under the pressure of 30MPa, and ground to obtain lithium tin alloy powder with the particle size of 50 mu m.
When the negative electrode is a slurry, the powder is added to a slurry of hard carbon negative electrode material. In the pulping process, the lithium-tin alloy powder is uniformly mixed with an active material, a binder and a conductive agent to prepare the pre-lithiated negative pole piece, so that the coulombic efficiency and the cycling stability of the first circle can be improved.
When the negative electrode is a pole piece, lithium is supplemented by hot pressing the lithium-tin alloy powder into the pole piece. Namely, the lithium-tin alloy powder is added on the surface of the negative pole piece and is rolled by a hot press, so that the lithium-tin alloy powder is combined with the pole piece to complete the pre-lithiation process, and the coulomb efficiency and the cycling stability of the first loop can be improved.
< example 2>
A20-micron-thick tin-copper alloy foil (wherein the mass percent of tin is 90 percent and the mass percent of copper is 10 percent) and a 50-micron-thick lithium belt are selected, pressed for 5 hours by a tablet press in a glove box under 40MPa, and ground to obtain 10-micron-diameter lithium-tin alloy powder.
When the negative electrode is a slurry, the powder is added to a silicon or silicon carbon composite slurry. In the pulping process, the powder, the active material, the binder and the conductive agent are uniformly mixed to prepare the pre-lithiated pole piece, so that the coulomb efficiency and the circulation stability of the first circle can be improved.
When the negative electrode is a pole piece, lithium is supplemented by hot pressing the lithium-tin alloy powder into the pole piece. Namely, the lithium-tin alloy powder is added on the surface of the negative pole piece and is rolled by a hot press, so that the lithium-tin alloy powder is combined with the pole piece to complete the pre-lithiation process, and the coulomb efficiency and the cycling stability of the first loop can be improved.
< example 3>
A30-micron-thick tin-cobalt alloy foil (wherein the mass percent of tin is 93 percent and the mass percent of zinc is 7 percent) and a 80-micron-thick lithium belt are selected, pressed for 8 hours by a tablet press in a glove box under 35MPa, and ground to obtain the lithium-tin alloy powder with the particle size of 20 microns.
When the negative electrode is a slurry, the powder is added to a slurry of graphite negative electrode material. In the pulping process, the powder, the active material, the binder and the conductive agent are uniformly mixed to prepare the pre-lithiated pole piece, so that the coulomb efficiency and the circulation stability of the first circle can be improved.
When the negative electrode is a pole piece, lithium is supplemented by hot pressing the lithium-tin alloy powder into the pole piece. Namely, the lithium-tin alloy powder is added on the surface of the negative pole piece and is rolled by a hot press, so that the lithium-tin alloy powder is combined with the pole piece to complete the pre-lithiation process, and the coulomb efficiency and the cycling stability of the first loop can be improved.
< example 4>
A20-micron-thick tin-zinc-antimony alloy foil (wherein the mass percent of tin is 90%, the mass percent of zinc is 5% and the mass percent of antimony is 5%) and a 50-micron-thick lithium belt are selected, pressed for 5 hours by a tablet press in a glove box under 40MPa, and ground to obtain lithium-tin alloy powder with the particle size of 30 microns.
When the negative electrode is a slurry, the powder is added to a tin-based negative electrode material slurry. In the pulping process, the powder, the active material, the binder and the conductive agent are uniformly mixed to prepare the pre-lithiated pole piece, so that the coulomb efficiency and the circulation stability of the first circle can be improved.
When the negative electrode is a pole piece, lithium is supplemented by hot pressing the lithium-tin alloy powder into the pole piece. Namely, the lithium-tin alloy powder is added on the surface of the negative pole piece and is rolled by a hot press, so that the lithium-tin alloy powder is combined with the pole piece to complete the pre-lithiation process, and the coulomb efficiency and the cycling stability of the first loop can be improved.
< example 5>
The method comprises the steps of selecting a tin-indium alloy foil with the thickness of 30 mu m (wherein the mass percent of tin is 90 percent, and the mass percent of indium is 10 percent) and a lithium belt with the thickness of 100 mu m, pressing for 6 hours by a tablet press in a glove box under the pressure of 40MPa, and grinding to obtain lithium-tin alloy powder with the particle size of 100 mu m.
When the anode is a slurry, the powder is added to an aluminum-based anode material slurry. In the pulping process, the powder, the active material, the binder and the conductive agent are uniformly mixed to prepare the pre-lithiated pole piece, so that the coulomb efficiency and the circulation stability of the first circle can be improved.
When the negative electrode is a pole piece, lithium is supplemented by hot pressing the lithium-tin alloy powder into the pole piece. Namely, the lithium-tin alloy powder is added on the surface of the negative pole piece and is rolled by a hot press, so that the lithium-tin alloy powder is combined with the pole piece to complete the pre-lithiation process, and the coulomb efficiency and the cycling stability of the first loop can be improved.
< test example 1>
The lithium tin alloy powder obtained in example 1 was examined by scanning electron microscopy and X-ray diffraction (XRD), and the examination results are shown in fig. 5 and 6.
Fig. 5 is a scanning electron microscope image of the lithium tin alloy powder in example 1 of the present invention, and fig. 6 is a graph of the X-ray diffraction (XRD) test result of the lithium tin alloy powder in example 1 of the present invention.
As shown in fig. 5, the morphology of the lithium tin alloy powder can be observed, with the particle size of the powder being approximately 50 μm.
As shown in fig. 6, the abscissa represents the diffraction angle of X-ray diffraction (XRD), and the ordinate represents the intensity of the peak. As can be seen from fig. 6, the lithium tin alloy powder obtained by comparing the PDF (diffraction database card) card, which has relatively strong diffraction peaks at 30 °, 32 °, 37 ° and 45 °, respectively, is Li3Sn. The above results indicate that we obtained lithium tin alloy powder by a simple mechanical preparation method, and that the obtained powder can be basically confirmed to be Li by XRD patterns3Sn is advantageous for the quantification of lithium addition for the subsequent prelithiation.
< test example 2>
The lithium tin alloy powder obtained in the example 1 is used as an active material, is uniformly mixed with a binder and a conductive agent according to the ratio of 8:1:1, is coated on a current collector and is dried to form a pole piece. Then assembling the obtained pole piece and the lithium piece into a half battery, wherein the battery assembling process comprises the following steps: and putting a commercial 500-micron lithium sheet into the negative electrode shell, then putting a PP diaphragm with the diameter of 16mm, adding 30-micron L of commercial electrolyte and wetting the diaphragm, then putting the prepared pole piece into the center of the diaphragm, enabling one surface containing the active material to face the lithium sheet, then sequentially putting a gasket, an elastic sheet and a positive electrode shell, and finally packaging the battery.
The battery test equipment is used for carrying out constant current charge and discharge test, and the specific test process is as follows: firstly, discharging the half cell at a current density of 0.1C, and stopping by taking the capacity as the cutoff until the capacity reaches 1 mAh; and (5) after standing for 2min, charging the full battery at the temperature of 0.1 ℃, and finishing charging when the voltage reaches 2V. The results of the battery test are shown in FIG. 7.
Fig. 7 is a voltage-capacity charge-discharge curve diagram of the battery in test example 2. Wherein the abscissa is the capacity and the ordinate is the voltage.
As can be seen from FIG. 7, the half-cell assembled with the lithium plate discharged 1mAh Li+The shell of the lithium tin alloy powder can be broken, and more lithium can be released, so that 1.16mAh Li can be charged+The lithium-tin alloy powder can be used as a lithium source for lithium supplement. The use of adding the powder to the slurry is more suitable for half cells. However, the method of rolling the powder by heating is more widely used, and both half cells and full cells can be used.
< test example 3>
A hard carbon negative electrode was prelithiated with the lithium tin alloy powder of example 1: adding the lithium-tin alloy powder in the example 1 into the hard carbon negative electrode material slurry, namely weighing and uniformly mixing the active material, the binder, the conductive agent and the lithium-tin alloy powder in the example 1 according to the mass ratio of 8:1:1:1 in the slurry preparation process to obtain a pre-lithiated pole piece, so as to obtain a pre-lithiated hard carbon negative electrode, and assembling the obtained pole piece and a lithium piece into a half-cell A. The process of assembling the half cell is as follows: and putting a commercial 500-micron lithium sheet into the negative electrode shell, then putting a PP diaphragm with the diameter of 16mm, adding 30-micron L of commercial electrolyte and wetting the diaphragm, then putting the prepared pole piece into the center of the diaphragm, enabling one surface containing the active material to face the lithium sheet, then sequentially putting a gasket, an elastic sheet and a positive electrode shell, and finally packaging the battery.
And then preparing a pole piece by using a hard carbon negative electrode without adding lithium tin alloy powder, assembling the pole piece into a half-cell B, wherein the preparation process of the pole piece and the assembling method of the half-cell are the same as those of the pole piece and the cell in the test example, and then assembling the obtained pole piece and the lithium piece into the half-cell B. Wherein the mass ratio of the active material to the binder to the conductive agent is 8:1: 1.
The battery test equipment is used for carrying out constant current charge and discharge test, and the specific test process is as follows: firstly, discharging the half cell at the current density of 0.1C until the voltage is cut off to 0V; standing for 2min, charging the full battery at 0.1C, and finishing charging when the voltage reaches 2.5V; and then, the whole battery is subjected to repeated charge-discharge cycle test under the condition of 0.2C, and the voltage range is still 0V-2.5V. This cyclic charge and discharge test was performed until the full cell discharge capacity was less than 80% of the initial discharge capacity. The charge and discharge test is a control experiment, the influence before and after the lithium tin alloy powder is added is compared, the half battery A is added with the powder for lithium supplement, and the half battery B is not added with the powder for lithium supplement and is used as a blank control. The results of the battery tests are shown in FIGS. 8-9.
Fig. 8 is a voltage-specific capacity diagram of half cell B in test example 3. Wherein, the abscissa is the specific capacity and the ordinate is the voltage.
Fig. 9 is a voltage-specific capacity graph of the half cell a in test example 3. Wherein, the abscissa is the specific capacity and the ordinate is the voltage.
As can be seen from fig. 8 to 9, the first-turn coulombic efficiency of the half cell B, which is the half cell of the hard carbon negative electrode that is not subjected to the pre-lithiation, is only 54.87%, while the first-turn coulombic efficiency of the half cell a, which is the half cell of the hard carbon negative electrode that is subjected to the pre-lithiation, can reach 78.40%, and it can be seen that the first-turn coulombic efficiency of the cell after the pre-lithiation is significantly improved, which indicates that the coulombic efficiency of the cell can be improved when the lithium-tin alloy powder is applied to the pre-lithiation process of the cell.
Effects and effects of the embodiments
Embodiments of the invention may be made by mechanical stress alloyingThe lithium tin alloy powder for supplementing lithium to the cathode material can well show the pre-lithiation effect and advantages, has air stability without being coated by an inert layer, has the particle size of 10-100 microns, and meets the commercial standard. The structure of the obtained powder can be determined through XRD detection, and the method is favorable for quantification of prelithiation added lithium. For example, the powder prepared in example 1 is Li3Sn having a particle size of 50 μm. Meanwhile, tin can also be used as an active material without reducing the capacity of the anode material, which makes the present invention have great industrial potential.
And adding the obtained lithium-tin alloy powder into the negative electrode through pulping or hot pressing to obtain a pre-lithiated negative electrode, and assembling the battery by using the negative electrode, so that the first-turn coulomb efficiency of the lithium battery can be improved. In the discharging process of the battery, the shell of the lithium-tin alloy powder is broken, so that more lithium can be released, and the lithium-tin alloy powder can be used as a lithium source for lithium supplement. For example, in test example 2, from the initial 1mAhLi+Increased to 1.16mAh Li+。
The negative electrode material may be a negative electrode material in the prior art, such as a graphite negative electrode material, a hard carbon negative electrode material, a silicon carbon negative electrode material, and the like.
In addition, the lithium tin alloy powder obtained by the embodiment of the invention can be used for lithium supplement of various cathode materials, and the cathode materials in the prior art can be basically added, so that the lithium tin alloy powder has a wide development prospect in a lithium supplement process of a lithium ion battery.
The above embodiments are preferred examples of the present invention, and are not intended to limit the scope of the present invention.
Claims (10)
1. A preparation method of lithium tin alloy powder for a lithium ion battery cathode is characterized by comprising the following steps:
flatly attaching a tin-based foil and a lithium strip together to obtain a stacked metal sheet;
pressing the stacked metal sheet by pressure equipment in a dry oxygen-free environment to enable the tin-based foil to be completely embedded into the lithium strip to obtain a lithium-tin alloy metal sheet;
and step three, grinding the lithium-tin alloy metal sheet into lithium-tin alloy powder by grinding equipment in a dry oxygen-free environment.
2. The method for preparing a lithium-tin alloy powder for a negative electrode of a lithium ion battery according to claim 1, characterized in that:
wherein, the particle size of the lithium tin alloy powder in the third step is 10-100 μm.
3. The method for preparing a lithium-tin alloy powder for a negative electrode of a lithium ion battery according to claim 1, characterized in that:
the tin-based alloy foil is an alloy consisting of tin and one or more of copper, silver, antimony, cobalt, zinc, antimony, bismuth and indium.
4. The method for preparing a lithium-tin alloy powder for a negative electrode of a lithium ion battery according to claim 1, characterized in that:
wherein the tin-based foil is pure tin foil.
5. The method for preparing a lithium-tin alloy powder for a negative electrode of a lithium ion battery according to claim 1, characterized in that:
wherein the pressure equipment is one of a hot press, a tablet press and a cold press,
the pressing process in the step two is as follows: and pressing the stacked metal sheets for 3-6 h under the pressure of 5-30 MPa by the pressure equipment to obtain the lithium-tin alloy metal sheets.
6. The method for preparing a lithium-tin alloy powder for a negative electrode of a lithium ion battery according to claim 1, characterized in that:
wherein, the thickness of the tin-based foil in the step one is 15-30 μm, and the thickness of the lithium belt is 40-100 μm.
7. The method for preparing a lithium-tin alloy powder for a negative electrode of a lithium ion battery according to claim 1, characterized in that:
wherein the pressure equipment is a roller press,
the pressing process in the step two is as follows: setting the distance between two roll shafts of the roller press to be smaller than the thickness of the stacked metal sheet, rolling the stacked metal sheet for 5-10 times through the roller press, and reducing the distance between the two roll shafts after each rolling.
8. A lithium-tin alloy powder for a lithium ion battery negative electrode, characterized in that the lithium-tin alloy powder for a lithium ion battery negative electrode is prepared by the method for preparing a lithium-tin alloy powder for a lithium ion battery negative electrode according to any one of claims 1 to 7.
9. The application of the lithium tin alloy powder for the lithium ion battery cathode in the lithium ion battery cathode is characterized in that:
wherein the lithium tin alloy powder is added as an active material to the lithium ion battery negative electrode,
the lithium tin alloy powder for a negative electrode of a lithium ion battery according to claim 8.
10. The application of the lithium tin alloy powder for the lithium ion battery cathode in the lithium ion battery cathode is characterized in that:
wherein the lithium tin alloy powder is hot-pressed into the lithium ion battery negative electrode as an active material,
the lithium tin alloy powder for a negative electrode of a lithium ion battery according to claim 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010135160.2A CN111313013A (en) | 2020-03-02 | 2020-03-02 | Preparation method and application of lithium-tin alloy powder for lithium ion battery cathode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010135160.2A CN111313013A (en) | 2020-03-02 | 2020-03-02 | Preparation method and application of lithium-tin alloy powder for lithium ion battery cathode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111313013A true CN111313013A (en) | 2020-06-19 |
Family
ID=71160302
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010135160.2A Pending CN111313013A (en) | 2020-03-02 | 2020-03-02 | Preparation method and application of lithium-tin alloy powder for lithium ion battery cathode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111313013A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112234160A (en) * | 2020-10-20 | 2021-01-15 | 陕西煤业化工技术研究院有限责任公司 | Lithium supplementing method for lithium ion battery negative electrode active material |
| CN112928258A (en) * | 2021-02-09 | 2021-06-08 | 合肥国轩高科动力能源有限公司 | Preparation method of pre-lithiated MXenes material and application of pre-lithiated MXenes material in battery electrode material |
| CN113422001A (en) * | 2021-07-23 | 2021-09-21 | 清华大学深圳国际研究生院 | Negative electrode prelithiation additive and preparation method and application thereof |
| CN115233020A (en) * | 2022-08-08 | 2022-10-25 | 深圳海润新能源科技有限公司 | Sodium-tin alloy, negative electrode, preparation method of negative electrode, battery and battery pack |
| CN117169748A (en) * | 2023-10-19 | 2023-12-05 | 荣耀终端有限公司 | Detection method for gram capacity of lithium-supplementing electrode slice |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1542997A (en) * | 2003-03-26 | 2004-11-03 | ������������ʽ���� | Electrode material for lithium secondary battery, electrode structure comprising the electrode material and secondary battery comprising the electrode structure |
| CN104956521A (en) * | 2012-12-19 | 2015-09-30 | 亿目朗美国股份有限公司 | Negative electrode active material for energy storage |
| CN105098138A (en) * | 2014-05-08 | 2015-11-25 | 微宏动力***（湖州）有限公司 | Negative plate used for lithium ion battery and preparation method thereof |
| CN105826545A (en) * | 2016-05-23 | 2016-08-03 | 天津巴莫科技股份有限公司 | Preparation method for lithium powder or lithium alloy powder |
| CN108565414A (en) * | 2018-03-28 | 2018-09-21 | 天津中能锂业有限公司 | Li-Si alloy material with finishing coat and preparation method thereof, electrode and electrochemical energy storage device, cathode mend lithium method |
| CN110707310A (en) * | 2019-10-29 | 2020-01-17 | 昆山宝创新能源科技有限公司 | Negative electrode material and preparation method and application thereof |
-
2020
- 2020-03-02 CN CN202010135160.2A patent/CN111313013A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1542997A (en) * | 2003-03-26 | 2004-11-03 | ������������ʽ���� | Electrode material for lithium secondary battery, electrode structure comprising the electrode material and secondary battery comprising the electrode structure |
| CN104956521A (en) * | 2012-12-19 | 2015-09-30 | 亿目朗美国股份有限公司 | Negative electrode active material for energy storage |
| CN105098138A (en) * | 2014-05-08 | 2015-11-25 | 微宏动力***（湖州）有限公司 | Negative plate used for lithium ion battery and preparation method thereof |
| CN105826545A (en) * | 2016-05-23 | 2016-08-03 | 天津巴莫科技股份有限公司 | Preparation method for lithium powder or lithium alloy powder |
| CN108565414A (en) * | 2018-03-28 | 2018-09-21 | 天津中能锂业有限公司 | Li-Si alloy material with finishing coat and preparation method thereof, electrode and electrochemical energy storage device, cathode mend lithium method |
| CN110707310A (en) * | 2019-10-29 | 2020-01-17 | 昆山宝创新能源科技有限公司 | Negative electrode material and preparation method and application thereof |
Non-Patent Citations (1)
| Title |
|---|
| HUI XU等: "Sn-Alloy Foil Electrode with Mechanical Prelithiation: Full-Cell Performance up to 200 Cycles", 《ADV. ENERGY MATER.》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112234160A (en) * | 2020-10-20 | 2021-01-15 | 陕西煤业化工技术研究院有限责任公司 | Lithium supplementing method for lithium ion battery negative electrode active material |
| CN112234160B (en) * | 2020-10-20 | 2022-02-11 | 陕西煤业化工技术研究院有限责任公司 | Lithium supplementing method for lithium ion battery negative electrode active material |
| CN112928258A (en) * | 2021-02-09 | 2021-06-08 | 合肥国轩高科动力能源有限公司 | Preparation method of pre-lithiated MXenes material and application of pre-lithiated MXenes material in battery electrode material |
| CN113422001A (en) * | 2021-07-23 | 2021-09-21 | 清华大学深圳国际研究生院 | Negative electrode prelithiation additive and preparation method and application thereof |
| CN115233020A (en) * | 2022-08-08 | 2022-10-25 | 深圳海润新能源科技有限公司 | Sodium-tin alloy, negative electrode, preparation method of negative electrode, battery and battery pack |
| CN117169748A (en) * | 2023-10-19 | 2023-12-05 | 荣耀终端有限公司 | Detection method for gram capacity of lithium-supplementing electrode slice |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111313013A (en) | Preparation method and application of lithium-tin alloy powder for lithium ion battery cathode | |
| EP3605664A1 (en) | All solid state battery and method for producing all solid state battery | |
| CN110537270B (en) | All-solid lithium ion secondary battery | |
| CN111952545B (en) | Pre-lithiated lithium ion secondary battery negative electrode material and mechanical pre-lithiation method thereof | |
| CN110534712A (en) | A kind of black phosphorus-titanium dioxide-carbon compound cathode materials and preparation method and application | |
| CN101937994A (en) | Graphene/aluminum composite cathode material of lithium ion battery and preparation method thereof | |
| CN113161602A (en) | Lithium ion battery cell, lithium ion battery and preparation method | |
| JP2018181702A (en) | Method for manufacturing all-solid lithium ion secondary battery | |
| CN114094068B (en) | Cobalt-coated positive electrode material, preparation method thereof, positive electrode plate and lithium ion battery | |
| CN101728514B (en) | Compound lithium iron phosphate of lithium ion battery positive electrode material and preparation method thereof | |
| CN112038579A (en) | Metal lithium composite electrode, preparation method thereof and electrochemical energy storage device | |
| CN112635763A (en) | All-solid-state battery | |
| CN112701281A (en) | Composite olivine structure positive electrode material and preparation method and application thereof | |
| CN111342049A (en) | Modified sodium ion battery positive electrode material, preparation method and battery | |
| CN112952185A (en) | Lithium ion battery and preparation method thereof | |
| CN112614979A (en) | Secondary carbon-coated lithium iron phosphate and preparation method thereof | |
| JP2018181706A (en) | Method for manufacturing all-solid lithium ion secondary battery | |
| CN116799210A (en) | Composite lithium supplementing material and preparation method thereof, lithium supplementing coating and preparation method thereof, and lithium battery | |
| CN112750989A (en) | Method for modifying lithium ion battery electrode material by using lithium ion conductor | |
| CN114613939B (en) | All-solid battery | |
| CN116470003A (en) | Pre-lithiated negative electrode piece and lithium ion battery | |
| CN113809419A (en) | Formation method and formed lithium ion battery | |
| KR20210131726A (en) | Lithium halide-based solid electrolyte, preparation method thereof and all-solid battery using the same | |
| JP6593381B2 (en) | Negative electrode mixture for all solid lithium ion secondary battery, negative electrode including the negative electrode mixture, and all solid lithium ion secondary battery including the negative electrode | |
| CN115465901B (en) | Method for completely coating surface of positive electrode material of lithium ion battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200619 |